YAP :Ce
Yttrium aluminum perovskite activated by cerium is a fast, mechanically and chemically resistant scintillation material. These scintillators have very low energy secondary X-ray emission, which is of advantage in imaging applications. YAP:Ce detectors are used for gamma and X-ray counting, electron microscopy, electron and X-ray imaging screens. The materials scintillation and mechanical properties enable their use in tomography systems.
Technical parameters
| Physical properties | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| YAP:Ce | YAG:Ce | LuAG:Ce | CRY 18 | LuAG:Pr | LuAP:Ce | BGO | PWO | CRY 19 | |
| Density | 5.37 g/cm3 | 4.57 g/cm3 | 6.73 g/cm3 | 4.5 g/cm3 | 6.73 g/cm3 | 8.34 g/cm3 | 7.13 g/cm3 | 8.28 g/cm3 | 7.1 g/cm3 |
| Hardness by Mohs | 8.6 | 8.5 | 8.5 | 5.8 | 8.5 | - | 5 | 4 | - |
| Index of refraction | 1.95 | 1.82 | 1.84 | 1.79 | 1.84 | - | 2.15 | 2.17 | 1.81 |
| Melting point | 1875°C | 1970°C | 2020°C | 1980°C | 2043°C | 1960 °C | 1050 °C | 1123 °C | 2100°C |
| Thermal expansion | 0.4-1.1 x 10-5/K | 0.8-0.9 x 10-5/K | - | - | - | - | 0.7 x 10-5/K | - | 1.8-10.3 x 10-5/K |
| Crystal structure | rhombic | cubic | cubic | monoclinic | cubic | - | cubic | tetragonal symetric | monoclinic |
| Hygroscopic | NO | NO | NO | NO | NO | NO | NO | NO | NO |
| Scintillation properties | |||||||||
| Wavelength of max. emission | 370 nm | 550 nm | 535 nm | 425 nm | 310 nm | 365 nm | 480 nm | 420 nm | 420 nm |
| Decay constant | 25 ns | 70 ns | 70 ns | 45 ns | 20 ns | 18 ns | 300 ns | 5-15 ns | 41 ns |
| Afterglow | <0.005 % at 6 ms | <0.005 % at 6 ms | - | - | - | - | <0.005% at 6 ms | - | - |
| Radiation length for 511 keV | 2.7 cm | 3.5 cm | 1.3 cm | 2.74 cm | 1.3 cm | - | 1.1 cm | 0.89 cm | 2.1 cm |
| Photon yield at 300 K (27°C) | 25 x 103 Ph/MeV | 30 x 103 Ph/MeV | 25 x 103 Ph/MeV | 30 x 103 Ph/MeV | 15-18 x 103 Ph/MeV | 11 x 103 Ph/MeV | 8-10 x 103 Ph/MeV | 15-25 phe/MeV | 24 x 103 Ph/MeV |
| Integrated light output compared to NaI:Tl | 70 % NaI:Tl | 40 % NaI:Tl | 20 % NaI:Tl | 80 % NaI:Tl | 66 % NaI:Tl | - | 15-20 % NaI:Tl | - | 75 % NaI:Tl |
